Instruments for preparing bone implants

ABSTRACT

A system includes a cutting guide and a cutting template. The cutting guide has a body including a plurality of sides that together define a cavity that is accessible via an opening defined by a first side of the plurality of sides. A second side of the plurality of sides defines at least two elongate slots. The second side is disposed adjacent to the first side and at a distance from an opposed third side. Each of the at least two slots is in communication with the cavity and disposed at a different location along the second side. The cutting template has a body defining at least one elongate slot. The cutting template is configured to be engaged with the cutting guide such that the at least one elongate slot of the cutting template aligns with at least one of the at least two elongate slots of the cutting guide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/974,856, filed Aug. 23, 2013, now U.S. Pat. No. ______, which is acontinuation of U.S. patent application Ser. No. 12/255,855, filed Oct.22, 2008, now U.S. Pat. No. 8,545,501, the entireties of which areincorporated by reference herein.

FIELD OF DISCLOSURE

The present invention relates to a system, kit, and method associatedwith surgical instruments, and more particularly to a system, kit, andmethod related to surgical instruments for preparing bone implants.

BACKGROUND OF THE INVENTION

Adult acquired flatfoot deformity or posterior tibial tendon dysfunctionis a gradual but progressive loss of a person's arch. The posteriortibial muscle is a deep muscle in the back of the calf that has a longtendon that extends from above the ankle and attaches into several sitesaround the arch of the foot. This muscle acts like a stirrup on theinside of the foot to help support and stabilize the arch and to createa rigid platform for walking and running. If the posterior tibial tendonbecomes damaged or tears, then the arch loses its stability andcollapses causing a flatfoot. There are various stages of the adultflatfoot deformity. At stage two, deformities usually require a surgicalbone procedure to recreate the arch and stabilize the foot. Theseprocedures include isolated fusion procedures, bone grafts, and/or therepositioning of bones through bony cuts called osteotomies.

Various osteotomies for correction of the adult flatfoot have beendeveloped and practiced. One such osteotomy, the Evans procedure, is acalcaneal osteotomy that lengthens the lateral column and realigns themidtarsal joint by reducing forefoot abduction. The Evans procedure alsoplantarflexes the first metatarsal and reduces talocalcanealsubluxation. Another osteotomy, the Cotton procedure, corrects theflatfoot deformity through a structural graft placed in the medialcuneiform. In both the Evans and Cotton procedures, a bone graft orimplant is placed in an osteotomy created in the foot of a patient. Boneimplants, such as the CANCELLO-PURE™ Evans and Cotton bone wedgesavailable from Wright Medical Technology, Inc., in Arlington, Tenn.,have been created for use in both types of osteotomies. As the size andshape of the foot varies from person to person, it is sometimesnecessary for a bone implant to be customized in the operating room (OR)so that the implant appropriately corrects the deformity. However,customizing a bone implant, during a surgical procedure is not easilyaccomplished as the bone implants are often formed from sterilizedanimal bone or allograft making them difficult to shape tableside.

SUMMARY OF THE INVENTION

In one embodiment of the present invention, a system for preparing abone implant includes a cutting guide having a body including aplurality of sides that together define a cavity that is accessible viaan opening defined by a first side of the plurality of sides. A secondside of the plurality of sides defines a plurality of slots and isdisposed adjacent to the first side. Each of the plurality of slots isin communication with the cavity that is sized and configured to receivea bone implant therein, and each of the plurality of slots is located ata different location of the second wall to facilitate cutting a boneimplant into one of a plurality of sizes.

In another embodiment of the invention, a method for preparing a boneimplant includes inserting a bone implant into an opening defined by afirst side of a plurality of sides of a cutting guide until the boneimplant is received within a cavity defined by the plurality of sides ofthe cutting guide. A blade of a chisel is inserted into at least one ofa plurality of slots defined by a second side of the plurality of sidesdefined by the cutting guide to cut the bone implant. The second side isdisposed adjacent to the first side, and each of the plurality of slotsis located at a different location of the second side to facilitatecutting a bone implant into one of a plurality of sizes.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bemore fully disclosed in, or rendered obvious by, the following detaileddescription of the preferred embodiments of the invention, which are tobe considered together with the accompanying drawings wherein:

FIG. 1 is a perspective view of a chisel for preparing a bone implantformed in accordance with present invention;

FIG. 2 is a side elevational view of the chisel for preparing a boneimplant shown in FIG. 1;

FIG. 2a is a bottom elevational view of the chisel shown in FIGS. 1 and2;

FIG. 3 is a top plan view of the chisel for preparing a bone implantshown in FIG. 1;

FIG. 4 is a distal-end-on view of the chisel for preparing a boneimplant shown in FIG. 1;

FIG. 5 is a cross-sectional view of the chisel for preparing a boneimplant as taken along line 5-5 in FIG. 3;

FIG. 6 is a cross-sectional view of the chisel for preparing a boneimplant as taken along line 6-6 in FIG. 3;

FIG. 7 is a cross-sectional view of the chisel for preparing a boneimplant as taken along line 7-7 in FIG. 2;

FIG. 8 is a perspective view of another chisel for preparing a boneimplant in accordance with the present invention;

FIG. 8a is a bottom elevational view of the chisel shown in FIGS. 8 and9;

FIG. 9 is a side view of the chisel for preparing a bone implant shownin FIG. 8;

FIG. 10 is a top plan view of the chisel for preparing a bone implantshown in FIG. 8;

FIG. 11 is a distal-end-on view of the chisel for preparing a boneimplant shown in FIG. 8;

FIG. 12 is a cross-sectional view of the chisel for preparing a boneimplant as taken along line 12-12 in FIG. 10;

FIG. 13 is a cross-sectional view of the chisel for preparing a boneimplant as taken along line 13-13 in FIG. 10;

FIG. 14 is a top side elevational view of a cutting guide in accordancewith the present invention;

FIG. 15 is a side view of the cutting guide shown in FIG. 14;

FIG. 16 is a bottom side elevational view of a cutting template inaccordance with the present invention;

FIG. 17 is a side view of the cutting template shown in FIG. 16;

FIG. 18 is a top side elevational view of the cutting template shown inFIG. 16;

FIG. 19 is a cross-sectional view of the cutting template as taken alongline 19-19 in FIG. 18;

FIG. 20 is a bottom side elevational view of another cutting template inaccordance with the present invention;

FIG. 21 is a side view of the cutting template shown in FIG. 20;

FIG. 22 is a top side elevational view of the cutting template shown inFIG. 20;

FIG. 23 is a cross-sectional view of the cutting template as taken alongline 23-23 in FIG. 20;

FIG. 24 is a top plan view of a chisel removal tool in accordance withthe present invention;

FIG. 25 is a side view of the chisel removal tool shown in FIG. 24;

FIG. 26 is a top plan view of another chisel removal tool in accordancewith the present invention.

FIG. 27 is a side view of a chisel removal tool shown in FIG. 26;

FIG. 28 is a perspective view of a slap-hammer chisel remover inaccordance with the present invention;

FIG. 29 is a side view of the slap-hammer chisel remover as shown inFIG. 28;

FIG. 30 is an end-on view of the slap-hammer chisel remover shown inFIG. 28;

FIG. 31 is a cross-sectional view of the slap-hammer chisel remover astaken along line 31-31 in FIG. 30;

FIG. 32 is a side view of a trial tool in accordance with the presentinvention;

FIG. 33 is a top plan view of the trial tool shown in FIG. 32;

FIG. 34 is a detail view of detail A shown in FIG. 32;

FIG. 35 is a top plan view of an impactor in accordance with the presentinvention;

FIG. 36 is a side view of the impactor shown in FIG. 35;

FIG. 37 is a detail view of the detail A in FIG. 35; and

FIG. 38 is a proximal end view of the impactor shown in FIG. 36.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

This description of the preferred embodiments is intended to be read inconnection with the accompanying drawings, which are to be consideredpart of the entire written description of this invention. The drawingfigures are not necessarily to scale and certain features of theinvention may be shown exaggerated in scale or in somewhat schematicform in the interest of clarity and conciseness. In the description,relative terms such as “horizontal”, “vertical”, “up”, “down”, “top”,and “bottom” as well as derivatives thereof (e.g., “horizontally”,“downwardly”, “upwardly”, etc.) should be construed to refer to theorientation as then described or as shown in the drawing figure underdiscussion. These relative terms are for convenience of description andnormally are not intended to require a particular orientation. Termsincluding “inwardly” versus “outwardly”, “longitudinal” versus “lateral”and the like are to be interpreted relative to one another or relativeto an axis of elongation, or an axis or center of rotation, asappropriate. Terms concerning attachments, coupling and the like, suchas “connected” and “interconnected”, refer to a relationship whereinstructures are secured or attached to one another either directly orindirectly through intervening structures, as well as both movable orrigid attachments or relationships, unless expressly describedotherwise. The instruments and methods are described by way of exampleas being used to shape and customize a bone implant that is to beinserted into an osteotomy formed in the foot of a patient. However,this description is for exemplary purposes and should not be construedto limit the scope of use of the disclosed instruments and methods.

Referring to FIGS. 1-7, a chisel 100 for preparing a bone implant formedin accordance with the present invention is often formed from anybiocompatible, engineering material that is suitably rigid and hard soas to be capable of shaping a bone implant without bending, breaking, orchipping, e.g., stainless or high carbon steel. Chisel 100 includes ahandle 102 having a distal end 102 a and a proximal end 102 b (FIG. 1).A chisel head 106 is located at distal end 102 a, and a transverselyexpanded or “mushroom” head 105 located at a proximal end 102 b. Handle102 may have a circular or polygonal cross-sectional shape often with awidth dimension that provides sufficient structural integrity to preventunwanted bending or breaking while fitting comfortably in the hand of asurgeon. Referring to FIG. 2, handle 102 includes a frustoconical neck104 at distal end 102 a which has a substantially cylindrical portion107 that projects outwardly from its distal end so as to connect to orengage with a rear portion of chisel head 106. Although shown as havinga tapering cross-sectional shape, in some embodiments, neck portion 104may have a constant cross-sectional shape that is larger or smaller thanthe cross-sectional shape of handle 102. Handle 102 may include knurlingor circumferentially arranged ribs 124 disposed along a substantialportion of its length to increase the ability of a surgeon to hold andmanipulate chisel 100 without it slipping. Knurling or circumferentiallyarranged ribs 124 may take the form of a plurality of concentric notchesformed along the length of handle 102, or may be replaced altogether orpartially by a roughened surface.

Chisel head 106 includes a stop 108 and a blade 110 (FIG. 2a ). Thecross-sectional shape of blade 110 includes a convexly curved topsurface 130 and a substantially planar bottom surface 132 (FIGS. 2a and7). Stop 108 extends radially from cylindrical portion 107, and includesa face 112 and a contact surface 114. Face 112 of stop 108 defines arectangular notch 116 having a width and length that together enableanother tool to engage chisel head 106, as will hereinafter be disclosedin further detail. Notch 116 often has a rectangular shape, one skilledin the art will appreciate that notch 116 may have any geometry thatfacilitates engagement with another tool. In some embodiments, notch 116extends transversely relative to the longitudinal axis of handle 102,and often communicates with bottom surface 132, although in someembodiments notch 116 may not communicate with bottom surface 132. Blade110 extends distally from face 112 of stop 108, and has a curvedcross-sectional geometry (FIG. 5). In some embodiments, the blade has acurved cross-sectional geometry that emulates the curvature of thelateral side of a calcaneus. The distal tip of blade 110 is swaged so asto taper to a cutting edge 118 that is suitable for cutting or shaping abone implant (FIG. 6). Referring to FIGS. 2, 2 a, and 3, mushroom head105 includes a proximal face 133 that may be used as a force bearingsurface if additional force is needed to shape a portion of the boneimplant. Mushroom head 105 may have any geometry including, but notlimited to, circular, oval, hexagonal, or rectangular. Mushroom head 105may include one or more flats 135 to prevent chisel 100 from rollingwhen placed on its side (FIG. 1).

Referring to FIGS. 8-13, a chisel 200 formed in accordance with thepresent invention includes a handle 202 having a distal end 202 a and aproximal end 202 b. A chisel head 206 is located at distal end 202 a,and a transversely expanded or “mushroom” head 205 located at a proximalend 202 b. Chisel handle 202 may have a circular or polygonalcross-sectional shape often with a width dimension that providessufficient structural integrity to prevent unwanted bending or breakingwhile fitting comfortably in the hand of a surgeon. Chisel handle 202may include knurling or circumferentially arranged ribs 224 disposedalong a substantial portion of its length to increase the ability of asurgeon to hold and manipulate chisel 200 without slippage.

Referring to FIG. 9, chisel head 206 includes a stop 208 having arectangular cross-sectional shape that is greater than thecross-sectional shape of handle 202. A rectangular notch 216 is formedin a distal face 212 of stop 208 (FIG. 8). One skilled in the art willappreciate that notch 216 may have other geometries in addition to arectangular geometry. Chisel head 206 includes a blade 210 that extendsdistally from a central portion of stop 208. Referring to FIGS. 11 and12, blade 210 may have a curved cross-section. In some embodiments, thecurved cross-section of blade 210 complements the curvature of thelateral side of a calcaneus. The distal end of blade 210 is swaged so asto taper to a cutting edge 218 that is suitable for cutting or shaping abone implant. The proximal side of stop 208 defines a contact surface214. Proximal end 202 b of handle 202 is connected to mushroom head 205,and includes a proximal face 222, and one or more flats 228 to preventchisel 200 from rolling when placed on a surface (FIGS. 8 and 11).

Referring to FIGS. 14 and 15, a cutting guide 300 formed in accordancewith the present invention includes a body 302 having a pair of tabs304. Each of tabs 304 extend outwardly from a side of body 302 inlongitudinally aligned, spaced relation to one another. Cutting guide300 is often formed any biocompatible, engineering material that issuitably rigid and hard so as to be capable of withstanding compressiveloads. Examples of such materials include, but are not limited tostainless steel and carbon steel. As shown in FIG. 15, tabs 304 may havea thickness that is less than the thickness of the body 302. One skilledin the art will appreciate that the thickness of tabs 304 may be variedto enable a person to hold and easily manipulate cutting guide 300.

An implant cavity 312 is defined by a trapezoidal recess formed withinbody 302 of cutting guide 300 (FIG. 15). Implant cavity 312 is oftensized and configured to accept a wedge-shaped bone implant such as, forexample, a CANCELLO-PURE™ Evans Bone Wedge available from Wright MedicalTechnology, Inc., of Arlington, Tenn. In some embodiments, implantcavity 312 has a height, length, and depth that is suitable forreceiving such a wedge-shaped bone implant having a height ofapproximately 12 mm, a length of approximately 28 mm, and a width ofapproximately 22 mm. One skilled in the art will appreciate that thegeometry and dimensions of implant cavity 312 may be adjusted to belarger or smaller to accommodate bone implants of various shapes andsizes. One or more alignment guides 314 extend across implant cavity312. In one embodiment, alignment guides 314 may comprise a pair of pinsthat are press fit into holes defined by body 302 of cutting guide 300.In other embodiments, alignment guides 314 may comprise fewer or morepins or be formed as one or more prongs or projections that serve toproperly align a bone implant within implant cavity 312.

As shown in FIG. 14, a top surface of cutting guide 300 also defines aplurality of curved openings that communicate with inwardly extendingpassageways that each create a curved slot 306 a, 306 b, 306 c, and 306d. The curvature of slots 306 a, 306 b, 306 c, and 306 d is selected soas to be complementary to the curvature of either blade 110 or blade210. Curved slots 306 a, 306 b, 306 c, and 306 d are spaced apart fromone another, and are often arranged in body 302 at graduated locations.In some embodiments, curved slots 306 a, 306 b, 306 c, and 306 d extendthrough body 302 of cutting guide 300 so as to allow communicationbetween a top surface and a bottom surface of body 302. Internalopenings in the walls of body 302, that define implant cavity 312,communicate with corresponding portions of curved slots 306 a, 306 b,306 c, and 306 d so as to be positioned longitudinally along implantcavity 312, and graduated with respect to one another. In this way, abone implant that has been positioned within implant cavity 312 may becut to one of several predetermined sizes by insertion of one of chisel100 or chisel 200 into successive ones of curved slots 306 a, 306 b, 306c, and 306 d. For example, a bone implant may be cut using slots 306 aand 306 d to create a bone implant having a thickness of 10 mm, slot 306b to create a bone implant having a thickness of 8 mm, and slot 306 c tocreate a bone implant having a thickness of 12 mm. One skilled in theart will appreciate that slots 306 may be provided in differentlocations of the body 302 to yield bone implants with a variety ofdimensions as necessary or desirable for a particular procedure orpatient. Cutting guide 300 also defines a round mounting hole 308 and arectangular or square mounting hole 310 that are each formed in the body302. In one embodiment, mounting holes 308 and 310 extend through theentire body 302 of cutting guide 300, and have different cross-sectionalgeometries. One skilled in the art will understand that cutting guide302 may have fewer or more mounting holes.

Referring to FIGS. 16-19, when a surgeon wishes to preselect aparticular implant length to be shaped with the present invention, acutting template 400 may be placed over the top surface of cutting guide300 so as to block all but one or two of curved slots 306 a, 306 b, 306c, and 306 d. More particularly, a cutting template 400 often has arectangular body 402 including substantially flat top and bottomsurfaces. A pair of spaced-apart studs 406, 408 project outwardly insubstantially perpendicular relation from the bottom surface of body402. One skilled in the art will understand that the number of studs maybe varied depending on the number of mounting holes are provided incutting guide 300. The top surface of cutting template 400 also definesa curved opening that communicates with an inwardly extending passagewayand another correspondingly located opening in the bottom surface ofcutting template 400. In this way, a curved slot 404 is formed thatextends through body 402. Curved slot 404 has a shape that correspondsto any one of curved slots 306 a, 306 b, 306 c, and 306 d. Studs 406,408 project outwardly from the bottom surface of cutting template 400.In the embodiment illustrated in FIGS. 16-17, stud 406 has asubstantially circular cross-sectional shape corresponding to thecross-sectional shape of round mounting hole 308, while stud 408 hasrectangular or square cross-sectional shape that corresponds to thecross-sectional shape of rectangular or square mounting hole 310 suchthat the cutting template 400 is keyed to the cutting guide 300regardless of the side to which the cutting template 400 is installed.One skilled in the art will appreciate that other geometries and sizesof studs 406 and 408 may be provided with adequate effect. When cuttingtemplate 400 mounted to cutting guide 300, such that stud 406 isreceived within round mounting hole 308 and stud 408 is received withinrectangular or square mounting hole 310, curved slot 404 may be quicklyidentified by a surgeon or other user as the remaining slots on cuttingguide 300 will be covered by body 402 of cutting template 400.Additionally, cutting template 400 may be numbered to identify the sizeof bone implant to be formed by its use. For example, a cutting template400 may be labeled “10” (not shown) if a bone implant with a thicknessof 10 mm is formed by its use.

Referring to FIGS. 20-23, another cutting template 500 includes a body502, one or more studs 506, 508, and two curved slots 504 a, 504 b thatare formed in substantially similar fashion to cutting template 400.Slots 504 a, 504 b are provided at locations on body 502 of cuttingtemplate 500 that will align with slots 306 a and 306 d of cutting guide300 when cutting template 500 is installed on cutting guide 300 in amanner substantially similar to that of cutting template 400. Oneskilled in the art will appreciate that the location of slots 504 a, 504b may be varied so that the bone implant is cut to the desireddimensions.

Referring to FIGS. 24 and 25, a chisel remover 600 includes a proximalend 602, a distal or insertion end 604, and a handle portion 606.Proximal end 602 and insertion end 604 may have a width that is thesmaller than, greater than, or equal to a width of the handle portion606. In one embodiment, chisel remover 600 may have a substantiallyconstant thickness with upper and lower surfaces being substantiallystraight. The insertion end 604 is sized such that it may be receivedwithin notch 116, 216 of chisel 100, 200. Chisel remover 600 may beformed from any suitable a biocompatible engineering material that hassufficient strength to be used to pry chisel 100, 200 from cutting guide300. Examples of such materials include, but are not limited totitanium, carbon steel, and stainless steel.

Referring to FIGS. 26 and 27, another embodiment of chisel remover 700.As shown in FIG. 27, chisel remover 700 may have a curvedcross-sectional profile 708 at or near a distal end 704 to enhanceleverage. In one embodiment, the curve or bend 708 is located at adistance “D” from distal end 704 so that the curve 708 pivots on a topsurface of the cutting template 400, 500 or cutting guide 300 when thedistal end is inserted into the slot 116, 216 of chisel 100, 200. Oneskilled in the art will appreciate that the distance D may be varied upto and including half the length of the total length of the chiselremover 700 so as to change the length of the lever arm.

Referring to FIGS. 28-31, a slap-hammer chisel remover 800 has a curvedbody 802 that defines a channel 804. Channel 804 is defined between twolongitudinally extending side walls 806 and a radiused base 808. An edgeportion of each of the ends 802 a, 802 b of body 802 may include achamfer 810 to facilitate engagement with handle 102, 202 of chisel 100,200. Frictional elements 812 may be formed on the outer surface ofslap-hammer chisel remover 800 to provide a gripping surface for asurgeon. Frictional elements 812 may be formed by a series of notches inthe outer surface of body 802 or any roughened or knurled surface thatprovides enhanced friction to facilitate gripping by a surgeon or otheruser. Slap-hammer chisel 800 may be formed from any material that hassufficient structural integrity to resist bending, breaking, or chippingwhen used. Examples of materials include, but are not limited to,titanium, carbon steel, and stainless steel.

Referring to FIGS. 32-34 a trial 900 may be formed from any materialthat has sufficient durability to be placed into and be removed from anosteotomy formed in a patient's foot. In some embodiments, trials 900are formed from a metallic material to provide contrast during afluoroscopic imaging procedure. Examples of such metallic materialsinclude, but are not limited to, aluminum, stainless steel, high-carbonsteel, and titanium. Trial 900 includes an elongate handle 902 and atrial head 908. Elongate handle 902 may include a neck portion 904 thatconnects to trial head 908. Neck portion 904 may have a reducedcross-sectional area relative to the cross-sectional area of elongatehandle 902 to provide clearance when inserting and removing trial 900from an osteotomy. Elongate handle 902 may also include frictionalelements 906 disposed along the length of handle 902. In one embodiment,frictional elements 906 may take the form of a plurality of concentricnotches formed in the outer surface of handle 902. In other embodiments,frictional elements 906 may be a roughened or knurled surface of thehandle 902. In one embodiment, a proximal end 912 of handle 902 may besubstantially flat to provide a striking surface for a hammer or otherconcussive instrument to facilitate insertion of trial head 908 into anosteotomy. In other embodiments, trial 900 may include a mushroomed orbroadened head or other feature that facilitates insertion into and/orremoval of trial head 908 from an osteotomy.

Trial head 908 has a trapezoidal cross-sectional profile that tapersfrom a thickness, T₁, adjacent neck portion 904 of handle 902 to adistal end 910 having a thickness T₂ (FIG. 34). Examples of thethickness T₁ of trial head 908 include, but are not limited to 8 mm, 10mm, and 12 mm. In one embodiment, thickness T₂ of distal end 910 oftrial head 908 may vary depending upon the thickness T₁ as the bonewedge implants are preformed and distal end 910 is formed to replicatethe distal end of a bone implant. The corners of trial head 908 may berounded to facilitate insertion and removal of trial head 908 into andout of an osteotomy without catching on or tearing skin, ligament, orother soft tissue. As shown in FIG. 33, trial head 908 has asubstantially rectangular cross-section, often with rounded corners. Inone embodiment, the length of trial head 908 is substantially equal tothe length of the bone implant that will be placed within an osteotomyin, e.g., a patient's foot.

Referring to FIGS. 35-38, an impactor 1000 includes a handle 1002, amushroomed or broadened head 1004, and an impacting end 1014. Handle1002 has a proximal end 1002 b and a distal end 1002 a. Mushroom head1004 radially extends from the proximal end 1002 b of handle 1002.Mushroom head 1004 includes a proximal face 1008 that may be used as aforce bearing surface if additional force is needed to drive the boneimplant into an osteotomy. Mushroom head 1004 may have any geometryincluding, but not limited to, hexagonal, circular, oval, orrectangular. As shown in FIG. 38, mushroom head 1004 may include one ormore flats 1010 to prevent impactor 1000 from rolling when placed on asurface. A radius or chamfer 1012 may be formed between mushroom head1004 and handle 1002 to provide an ergonomic fit with the hand of asurgeon or user.

Impacting end 1014 is disposed at proximal end 1002 b of handle 1002. Inone embodiment and as shown in FIG. 36, impacting end 1014 has a smallerthickness than the thickness of handle 1002. In some embodiments, thethickness of impacting end 1014 is greater than or equal to the smallestthickness of the wider end of a prepared bone implant to enable impactor1000 to impact a bone implant such that the entire bone implant fitswithin the osteotomy. For example, if a bone implant has a wide end of 8mm, then the thickness the impacting end 1014 is equal to or less than 8mm.

Referring now to FIG. 37, impacting end 1014 may include extensions 1016that extend outwardly from handle 1002. However, in some embodiments,impactor 1000 does not include extensions 1016. Impacting end 1014 maydefine a concave surface 1018 between the extensions 1016. The curvatureof the concave surface is complementary with the curvature of the blade110, 210 of chisel 100, 200. In some embodiments, the width W ofimpacting end 1014 is less than or equal to the width of a bone implant.However, one skilled in the art will appreciate that the width W of theimpactor 1000 may be varied.

The instruments for preparing bone implants may be included in a kit.The kit may include one or more trials 900 that may be used by a surgeonor other operating room personnel to determine the size of a boneimplant that will be inserted into an osteotomy created in a foot of apatient. For example, the kit may include a trial 900 for an implanthaving a thickness of 8 mm, 10 mm, and 12 mm. The kit may also include achisel 100, 200 for cutting and shaping a bone implant. A cutting guide300 for facilitating the cutting of the bone implant with chisel 100,200 along with one or more cutting templates 400, 500 may also beincluded in the kit. A chisel remover 600, 700, 800 may also be includedin the kit to aid in the removal of the chisel 100, 200 from the cuttingguide 300 after a bone implant has been shaped. Additionally, animpactor 1000 may be included to assist in the insertion of the sizedbone implant into the osteotomy located in the patient's foot.

Referring to FIGS. 1-38, a method for preparing a bone implant is nowdescribed. A surgeon performing an Evans procedure may make an obliqueincision centered over the distal lateral calcaneus while avoiding theintermediate dorsal cutaneous nerve superiorly and the sural nerveinferiorly. The depth of the incision may be increased through thesuperficial fascia to expose the lateral surface of the calcaneus. A cutmay be made through the calcaneus using a sagittal saw approximately oneto one and a half centimeters proximal to the calcaneocuboid joint.

A spreader may then be used to open the osteotomy and lengthen thelateral column. Once the lateral column is lengthened, a trial 900 maybe inserted into the osteotomy. With the trial located in the osteotomy,the distractor may be loosened. In some instances, the trial 900 withthe smallest thickness, e.g., a thickness of 8 mm, may be inserted intothe osteotomy. Forefoot correction and talonavicular coverage may bedetermined fluoroscopically with the trial 900 still located within theosteotomy. If additional correction or coverage is needed, the trial 900is removed and a trial having a larger thickness, e.g., 10 mm or 12 mm,is inserted. With a trial 900 having a larger thickness located withinthe osteotomy, the forefoot correction and talonavicular coverage mayagain be fluoroscopically checked.

Once the sizing of the implant is determined, the cutting template 400,500 corresponding to the size of the trial 900 that is determined toprovide the desired correction and coverage is installed to the cuttingguide 300. For example, if it is determined that the 10 mm trial 900provides the desired amount of forefoot correction and talonavicularcoverage, then the 10 mm cutting template 500 is selected and the roundprotrusion 506 and square protrusion 508 of cutting template 500 areplaced into the corresponding round and square mounting holes 308, 310of cutting guide 300. A wedge-shaped bone implant may be placed withinthe implant cavity 312 of cutting guide 300 either before or after thecutting template 400, 500 is installed to the cutting guide 300.

With the bone implant located within the implant cavity 312, a chisel100, 200 may be used to cut the bone implant to the desired size. Forexample, the blade 210 of chisel 200 may be first placed into slot 504 aof the cutting template 500 that aligns with slot 306 a of the cuttingguide 300. The blade 210 is slid into the slots 504 a and 306 a so thatthe cutting surface 218 of the chisel 200 makes contact with thewedge-shaped bone implant. A force is applied along the axis of thechisel 200 so that the blade 210 extends through and severs the boneimplant.

A mallet, hammer, or other tool may be used to strike the proximal face222 of the mushroom head 205 of chisel 200 until the distal face 212 ofstop 208 makes contact with the cutting template 500. Alternatively, theslap-hammer chisel remover 800 may be used to apply an impact forcealong the axis of the chisel 200. To use the slap hammer 800, thechannel 804 of the slap-hammer 800 is placed around the handle 202 ofthe chisel 200. Note that the channel 804 is sized to receive the handle202 of chisel 200 slidably therein. Once the handle 202 of the chisel200 is disposed in the channel 804 of the slap-hammer 800, the surgeonmay slide the slap-hammer 800 from an initial position located near themushroom head 205 towards the chisel head 206 so that an end 802 a, 802b of slap-hammer 800 contacts the contact surface 214 of the stop 208.If required, the slap-hammer 800 may be repeatedly slid along the handle202 of the chisel 200 to make contact with the proximal face 214 of stop208 until the blade 210 of chisel 200 severs the bone implant. The blade210 of chisel 200 is sized to ensure that it will fully cut through thewedge-shaped bone implant, but will not protrude through the oppositeside of cutting guide 300.

Once the chisel 200 severs the bone implant, the blade 210 is withdrawnfrom slots 306 a and 504 a of the cutting guide 300 and cutting template500, respectively. In some instances it may be difficult to remove theblade 212 of the chisel 200 from the slots of the cutting guide 300 andcutting template 500. In these instances, a chisel remover 600, 700 maybe used to remove the chisel 200 from the cutting guide 300. To removechisel 200 from cutting guide 300 using chisel remover 700, the distalend 704 of chisel remover 700 is inserted into the notch 216 located inthe stop 208 of the chisel 200. The distal end 704 of chisel remover 700is inserted into the notch 216 such that handle portion 706 protrudesfrom the surface of the body 302 of cutting guide 300 at an angle. Aforce perpendicular to the top surface of the cutting guide 300 may thenbe applied to the proximal end 702 of chisel remover 700. One or more ofthe tabs 304 of the cutting guide 300 may be held to maintain thecutting guide 300 in a fixed position. The application of force to theproximal end 702 of the chisel remover 700 works to pry to chisel 200from slot 504 a of the cutting template 500 and slot 306 a of cuttingguide 300.

Alternatively, the slap-hammer chisel remover 800 may be used to removechisel 200 from the slots of the cutting guide 300 and cutting template500. The channel 804 of slap-hammer 800 is placed around the handle 202of chisel 200. With the handle 202 of chisel 200 disposed within thechannel 804 of slap-hammer 800, the surgeon or user slides theslap-hammer 800 from an initial position located near the stop 208towards the mushroom head 205 so that an end 802 a, 802 b of theslap-hammer body 802 contacts the mushroom head 205. If required, theslap-hammer 800 may be repeatedly slid along the handle 202 such thatthe slap-hammer makes contact with the mushroom head 220 of chisel 200until the blade 210 of chisel 200 is free from the cutting guide 300 andcutting template 500.

Once the chisel 200 is dislodged from the cutting guide 300 and cuttingtemplate 500, the bone implant may be cut a second time using slot 504 bof the cutting template 500 and slot 306 d of the cutting guide 300 asguides. The process of cutting the bone implant a second time is similarto the process described above with respect the first cut using slots504 a and 306 a as guides. Once the bone implant has been shaped, it isremoved from the cutting guide 300. If additional shaping of the implantis needed, a bone rongeur, sagittal saw, or the chisel 200 may be usedto further shape the implant.

The implant is then inserted into the osteotomy. The impactor 1000 maybe used to facilitate the placement of the shaped implant in theosteotomy. For example, the thinner end of the bone implant may beintroduced into the osteotomy and then the impactor 1000 may be used toadvance the implant into the desired location. To advance and positionthe implant within the osteotomy, the impacting end 1014 of the impactor1000 is placed against the exposed surface of the implant. As describedabove, the concave surface 1018 of the impacting end 1014 has acurvature that is similar to the curvature of the blade 210 of thechisel 200, and thus the cut surface of the bone implant will be engagedby the concave surface 1018 of the impactor 1000. The surgeon or usermay then apply a force parallel to the axis of the impactor handle 1002to advance the implant into the osteotomy. In some instances, a hammer,mallet, or other instrument may be used by the surgeon to strike theproximal face 1008 of the mushroom head 1004 of the impactor 1000 to aidin the advancement of the bone implant into the osteotomy. Desirably,the implant should be located in the osteotomy such that its exterioredge is flush with the host bone.

The impactor 1000 may also be used to adjust the dorsal and plantarposition of the bone within the osteotomy. For example, if the wedge isdisposed within the osteotomy such that the exterior surface of theimplant is flush with the host bone, but the implant is not centeredwithin the bone, then the impactor 1000 may be used to center theimplant. The impactor 1000 may be used to center the implant within theosteotomy by applying a force to the impactor 1000 in a similar manneras described above with the exception that the impactor 1000 is notcentered on the exterior surface of the implant. The extensions 1016 ofthe impactor 1000 enable the impactor 1000 to reach a side of theimplant while the implant is disposed within the osteotomy.Additionally, since the width of the impacting end 1014 is less than orequal to the thickness of the thickness of the implant, the extensions1016 are able to be advanced along a side of the implant withoutcontacting bone.

Once the implant is positioned at the desired location within theosteotomy, a plate or other fixation device may be installed across theosteotomy to prevent the implant from backing out of the osteotomy. Theincision may then be closed using conventional methods known in the art.

Although the invention has been described in terms of exemplaryembodiments, it is not limited thereto. Rather, the appended claimsshould be construed broadly, to include other variants and embodimentsof the invention, which may be made by those skilled in the art withoutdeparting from the scope and range of equivalents of the invention.

1.-12. (canceled)
 13. A method, comprising: placing a cutting template into contact with a cutting guide such that at least one elongate slot defined by the cutting template aligns with at least one of at least two elongate slots defined by a first side of the cutting guide, wherein the cutting guide includes a body including a plurality of sides that together define a cavity that is accessible via an opening defined by a second side of the plurality of sides, the second side of the plurality of sides disposed adjacent to the first side and at a distance from an opposite third side, each of the at least two elongate slots defined by the cutting guide being in communication with the cavity and disposed at a different location along the first side.
 14. The method of claim 13, further comprising inserting a bone implant into the opening defined by the second side of the plurality of sides of the cutting guide until the bone implant is received within the cavity.
 15. The method of claim 13, wherein placing the cutting template into contact with the cutting guide includes inserting a stud extending from the cutting template into an aperture defined by the cutting guide.
 16. The method of claim 13, further comprising inserting a blade of a chisel into at least one of the at least two elongate slots defined by the first side of the plurality of sides of the body of the cutting guide to cut the bone implant.
 17. The method of claim 16, further comprising: determining the size of an implant using a trial; and selecting a cutting template that corresponds to the size of the trial.
 18. The method of claim 17, further comprising inserting the cut bone implant into an osteotomy formed in a patient's foot.
 19. The method of claim 18, further comprising removing the chisel from the at least one of the at least two elongate slots using a chisel remover, the chisel remover including a body having a distal end and a proximal end, wherein the distal end is sized and arranged to be received within a notch defined by the chisel.
 20. The method of claim 13, wherein placing the cutting template into contact with the cutting guide includes inserting a first stud extending from a surface of the cutting template into a first aperture defined by the cutting guide; and inserting a second stud extending from the surface of the cutting template into a second aperture defined by the cutting guide. 